The invention relates to a device for pushing glass objects from a dead plate of a section of an I.S. (individual section) glassware forming machine onto a conveyor belt.
Devices of this type are used as pushers in the production of hollow glass articles. They are used to transfer the article, which has been removed from a blow mold and set down on a stationary dead plate, onto a conveyor belt moving continuously at a uniform speed. The articles must be positioned on the conveyor belt standing one behind the other and then move into a lehr. Since, in the case of IS (individual section) machines, the conveyor belt cooperates with a plurality of manufacturing stations, each of which is provided with a dead plate, the process of pushing the hollow glass objects must take place within a time interval which is dependent on the working cycle of the other manufacturing stations and the conveying speed of the belt, wherein the pushing action must also be applied in such a way as to avoid the hollow glass objects falling over or being damaged as well as to avoid imprecise positioning on the belt. At the end of the transfer movement each hollow glass article must stand in a defined position on the belt and move with, and at the same speed as, the belt.
A device of this type is known from DE 10 2004 010 238 B3. Here, a first lever, which can swivel at one of its ends about a vertical, fixedly disposed axis, supports, at its other end and also in such a way as to swivel about a vertical axis, one end of a second lever, on the other end of which a pusher fitted with three pushing fingers is mounted also to be able to swivel about a perpendicular axis. Three mutually independently controllable, fixedly disposed drives are assigned to the rotations of the first lever about the stationary axis, of the second lever with respect to the first lever and of the pusher with respect to the second lever, wherein from the superimposition of the three partial movements generated by these drives, a transfer curve beginning at a reception point on the dead plate and ending at a delivery point on the conveyor belt can be provided. The transfer of the rotational motions of the three drives via the levers as far as the pusher is effected by means of toothed belt transmissions, the operation of which is considered to be maintenance-intensive. A high level of complexity results from an initial assembly using hollow shafts which are inserted one inside the other and subsequent separation for the purpose of introduction into the respective component, the rotational speed of which is to be controlled.
A further comparable device is known from EP 1 627 858 B1. Here, a first lever, which can swivel at one of its ends about a vertical, fixedly disposed axis, supports, at its other end and also in such a way as to swivel about a vertical axis, one end of a second lever, on the other end of which a pusher is mounted, once again so as to swivel about a perpendicular axis. Mutually independently controllable drives, which may be fixedly disposed, are assigned to the rotations of the first lever about the stationary axis, of the second lever with respect to the first lever and to that of the pusher with respect to the second lever. In this embodiment the formation of a chain consisting of the three drives, the second lever, the first lever and the pusher appears to be comparatively elaborate, wherein at one end of this chain the three partial movements are introduced and transferred one after another into the said components, since e.g. numerous transmission stages are required merely for the transfer of the rotation—effecting the partial movement of the pusher—of the assigned stationary drive.
Since these devices are used under the operating conditions of hollow glass manufacturing, i.e. in an atmosphere characterized by heat, dirt and moisture, and in particular abrasive materials, then with regard to the expected standing time, but also with regard to maintenance costs, precautions for protection against these environmental influences are essential. However, this prior art discloses absolutely no measures leading to a solution to this problem.